Purpose: To determine the radiation dose-response relationship on salivary dysfunction and quality of life (QOL) over time in patients with lymphoma receiving radiation therapy (RT) to the head and neck (H&N).
Methods and materials: We conducted a prospective study on salivary-gland function in lymphoma patients receiving RT to the H&N. Fifteen patients were enrolled on the study. Dose-volume histograms and mean doses to the salivary glands were generated. Radiation-related toxicities and H&N-specific QOL were assessed before treatment and at prespecified time points posttreatment. Factors predicting a decrement in QOL were explored using Fisher's exact test.
Results: During RT, 47% of patients experienced Grade >or= 2 acute toxicity of the salivary gland, mucous membrane, or both. QOL scores improved over time, but up to one third of patients continued to have persistent oral symptoms at 2 years. At 6 months, a mean dose to at least one of the parotids of > 31 Gy was significantly associated with persistent dry mouth (100% vs. 17%, p = 0.02) and sticky saliva (100% vs. 25%, p = 0.04); a mean dose of > 11 Gy to the minor salivary glands was significantly associated with persistent sticky saliva (100% vs. 25%, p = 0.04), although the difference was no longer significant at 1 year.
Conclusions: Limiting the mean parotid dose to <or= 31 Gy and mean minor salivary gland dose to <or= 11 Gy in lymphoma patients treated to the H&N may help reduce the risk of subacute xerostomia.